A153220 Self-locating strings within Pi: numbers n such that the string n is at position n (counting 3 and the decimal point) in decimal digits of Pi.

4, 315, 360, 384, 47696, 496498, 1577526, 5607861220, 6106488294

Offset: 1

Author

Gil Broussard, Dec 21 2008

Keywords

• base
• more
• nonn
• changed

Comments

a(8) > 10^9. - Vaclav Kotesovec, Feb 18 2020

Examples

			a(1)=4 because the 4th character (including the decimal point) in 3.14159... is also a 4.
		

Crossrefs

Cf. A057679, A057680, A109513, A109514

Programs

Mathematica

dpi = RealDigits[Pi, 10, 10000010][[1]]; Select[Range[2, 10000000], FromDigits[Take[dpi, {# - 1, # - 2 + IntegerLength[#]}]] == # &] (* Vaclav Kotesovec, Feb 18 2020 *)

Extensions

a(7) from Vaclav Kotesovec, Feb 18 2020

a(8)-a(9) from Guixin Lai, Aug 22 2025